Use of coil valve springs instead of hairpins on H/W singles

Helpful information and requests for assitance and advice
LynP
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by LynP »

Thank you to all who have contributed to this thread and have contacted me with their knowledge and contacts. I have looked back at previous posts but have not yet found a complete description/list of the parts that have been used in the conversion to coil springs on my 350. One day in the future I will take the head of my engine and measure everything which should help find their original applications .
MikeM.
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by MikeM. »

You could try speaking to Les at Russell Motors at Clapham Junction. He has more than enough experience of all things AMC, I have known him since at least 1974 and always found him very helpful.
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ajscomboman
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by ajscomboman »

Ken De Groome has carried out 2 coil conversions for me in the last few years so has all the info to hand as he does it on a regular basis.
56G80S
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by 56G80S »

Resurrecting this thread as I have the head and barrel off. Spriddler, when checking the free length I have a "daft" question. When using my magnificent Lidl digital vernier, do I check to the centre of the wire, the inside of the wire or the outside of the wire? (not the sausage sandwich game for those who've listened to Danny Baker).

I need to verify tomorrow but I recall that when I last had the head off (about 6K ago, maybe more) the springs were close to the limit but I don't recall which of the three options above I used. There was (and is now more) marking where the collet collar bears on the springs and some flattening where thay bear on the bottom tray.

At £126 a pair I am tempted to put in some coil springs insteadas no-one sees the things anyway. Any sourcing guidance on this would be welcome as well.

But I won't fit the spare hairspring set that I found which I realised where from the previous 14CSR!

Newly liner'd barrel is supposed to be back on Monday with new piston curtesy of T&L

Need to get run in for the Jampot.

Johnny B
LynP
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by LynP »

I am glad this post has resurfaced as I am still interested in this conversion, but referring back to my original post I did manage to get some hairpins at a sensible price so fitted them. However, I would like to do a spare head using coils springs.
SPRIDDLER
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by SPRIDDLER »

56G80S wrote:Spriddler, when checking the free length I have a "daft" question. When using my magnificent Lidl digital vernier, do I check to the centre of the wire, the inside of the wire or the outside of the wire?
The gap *should* be between 2" and not less than 1 11/16", so measure from the inside of the wire at the end of the 'cut' ends to the inside of the wire at the end of the ' loop' end. Since this allows a generous tolerance of 5/16" a tired spring will be pretty obvious. ;)
.
If my springs were not under the min I'd be tempted to reuse them. If in the future you feel you MUST replace them (due to valve bounce at high revs?) it's not a huge job requiring much work to replace them. The H/W touring engines are pretty agricultural and unstressed. If money was no object you could buy new springs on the basis that you're already committed to doing some rather costly and time-consuming repairs. However, I have no experience of the quality or longevity of pattern springs; some pattern parts seem to be suitable only for 'rosette' bikes. You make long trips but one has to consider how many miles it has already taken for them to become as they are now. I seem to remember your bike has been in the family or your ownership for many years so perhaps you know.

The info re the spring gap is from a very practical article on rebuilding H/W engines in Classic Mechanics by a well respected ex AMC dealer Ken Bryant, (known as 'ITMA' and very active on the Forums until some years ago)

http://archives.jampot.dk/technical/Spe ... hanics.pdf
Last edited by SPRIDDLER on Fri Jul 21, 2017 9:21 am, edited 1 time in total.
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56G80S
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by 56G80S »

Sprid, thanks for the guidance.

Yes, these are the same springs that were in place when I was first hacking up and down to London on the Matchless starting from about 1974. In part it's the longer trips and that coil springs are perhaps more readily available if needed that was in my mind.

I'd previously downloaded and have saved Ken's article but putting the link up will be good for anyone else. I remember Ken's posts well and enjoyed the by play between him and Alan Jacobs (the latter "Biscuit" was helpful to me personally). Alan's death was a loss and Ken seemed to become disenchanted with the repetitive nature of some of the queries, rather as does Rob, when people fail to use the Search facility. It's understandable.

I'm off to check the springs now. As for valve bounce at high revs, I assume that's your waspish sense of humour at play again!

Although I have to confess I am guilty of failing to give the respect to the Matchless that it's years deserve.

My plan is to do some more work during the winter, so I'll probably just refit the the hairsprings. Planned work work will include checking the timing side bush which i must've thought needed examination because I was recently checking my stock of new parts and there's a new bush in there. Not to mention sterring head ball bearings, new kit to refit the steering damper which has been off for years, and lots of other parts.

I'll also be getting the "stud" that I snapped off the SH exhaust cam properly replaced (instead of the self tapping screw that I used) and maybe take another look at the front wheel rim plus lots of other jobs. Trip to IJR Portugal will be well prepared for.

Johnny B
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by SPRIDDLER »

It's all down to how far you go in replacing marginally worn bits and my concern is that some pattern parts are not as good as the worn but useable originals. I would assume that many pattern hairsprings must have been fitted and proved satisfactory, but......?

To digress off topic if I may, I have spent many hours nattering with Ken over a brew in his sheds at his cottage in the woods, surrounded by all manner of 'one day I'll fix that' projects, from WD bikes to antique lawn mowers, a French moped or two, generator sets, chaff cutters, a collapsing Transit van stuffed full of soggy paperback books, a crumbling Morris Minor and a Grey Fergie tractor, beer barrel of 1 old penny coins..........
His patience was already largely exhausted in the dealership he owned for many years in South London when on Saturday mornings chaps used to pick his brains about problems with their bikes. He'd tell 'em the solution, how to do it, and which parts they'd need. The following Saturday they'd come back with another problem having fixed the previous one with parts they'd bought by mail order more cheaply. Either that or they were still thinking about it because: 'a chap down the pub said........'. His amusing anecdotes were endless.
It's understandable that folk need help these days in finding info to fix their bikes since although every question has been asked and answered numerous times it's knowing that the info is available by searching on here or on t'internet generally and knowing where to find it that is the key, but as they say: 'Information isn't knowledge'.
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56G80S
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by 56G80S »

'Information isn't knowledge' yes, that's a bit like the modern misunderstanding that data, as copiously provided by computers in a wide variety of formats whether using databases or spreadsheeets, is the same as analysis. In fact there's a Microsoft advert recently on TV which implies as much; Bill Gates is a very rich numpty but his wife is a terrific person who is the driving force behind all the philanthropic activities that his money is used for.

On topic, I checked the hairsprings and of course, thrown by the fact that the battery had died in the Lidl digital vernier, used Mum's old vernier and measured from outside to outside! Nonetheless, the inlet ones were at 2 1/8" both and one exhaust was a tad over 2 1/16" and the other was 2" exactly - so even allowing for the "wire" thickness should be OK. One of the exhaust springs has a sort of cut or nick mark on it that was there last time I put them back in, almost like someone had used a very small cutting disk on it. Had thought of stoning it out but as it's done thousands of miles like it will leave alone. I think I will swap the inlet and exhaust over as it looks like the exhaust is having a harder time!

Johnny B
56G80S
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Re: Use of coil valve springs instead of hairpins on H/W sin

Post by 56G80S »

Steve Surbey, helpful as ever, sent me an email that the supplier he is aware of is Russell's.

But is also of the view if the current springs aren't very worn, particularly where the collar bears on the spring, keep using the ones you have.

Johnny B
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